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  <title>Document</title>
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  <script>
    async function app() {
      let a = await new Promise((resolve) => {
        setTimeout(() => {
          console.log('promise---a');
          resolve('你好a')
        }, 1000)
      })
      let b = await new Promise((resolve) => {
        setTimeout(() => {
          console.log('promise---b');
          resolve('你好b')
        }, 1000)
      })
      console.log('lll');

    }
    app()


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